“Types of snakes”
Found a gene that determines, will become a gamete sperm or egg
Japanese genetics found in the DNA of fish unusual gene that determines it, will the sex cell sperm or egg, and changed his work so that in the ovaries of female fish began to form spermatozoa and in the testes of males of the egg, according to a paper published in the journal Science .
“We knew that gametes can turn into sperm and ovum, but no one has suggested that these cells in the vertebrate animals have a special gene”switch” that determines their fate – to become a sperm or egg. Our results indicate that the cell is able to go all the way. This is a very important and unexpected discovery” – quoted by RIA “Novosti” scientist Minoru Tanaka from the Institute of General biology of Japan in the city of Okazaki.
Tanaka and his colleagues made this unusual discovery, watching the development of germ cells in testes and ovaries rice fish-oriii (Oryzias latipes). During maturation of sperm and egg cells, researchers monitored changes in the level of activity of different genes, trying to find the differences between future male and female reproductive cells.
The attention of scientists was attracted to gene foxl3 – “archival copy” of the gene foxl2, which is responsible for growth of eggs and maintaining their existence in the body of the expectant mother. The role and work foxl3 of little interest to biologists up to the present time, and remained unknown.
As found by the authors, foxl3 is a kind of sexual “switch”, the active position which means that a gamete will develop into the egg and then into the egg, and turned off in the sperm.
To check this assumption, Japanese biologists went on an unusual experiment – they damaged the gene in the embryos of females of the rice fish, and forcibly “included” foxl3 in the germ cells of future males.
This technique has led to surprising results – when orisia were born, in the testes of individuals of the stronger sex started to form egg cells and ovaries in females – are the real sperm. When sex cells grew, scientists extracted them from the body of the fish and examined whether they can give life to a new generation of fish.
As it turned out, these gametes were viable, “female” sperm has successfully penetrated into oocytes of females from the control group and those given a healthy offspring, and a male egg was fertilized and turned into embryos.
What does this mean? First, the existence of this “switch” can explain why some species of snakes and fish saws are capable of self-replication. In favor of this speaks the fact that in the womb of the females arise, despite the damage foxl3, there were some eggs, which by the end of the experiment was fertilized.
Secondly, gene foxl3 or its analogs in DNA land animals can be used for conservation and saving endangered species. Today biologists are offered to save endangered species by growing them in egg and sperm cells from cultures of stem cells that can bring a lot of mutations in the germ and cause other unpredictable consequences. Manipulation of the genome foxl3 can reduce this risk.